Original description: Trinitella Brönnimann 1952: Test trochoidal, elongate in direction of end chamber. Chambers truncate at apertural side, increasing in size as added (end chamber about twice the size of the penultimate one), subglobular in major portion of adult whorl, flattened at the spiral side and peripherally keeled in the end stage. Chambers arranged in about 2 whorls, those of the last volution overlapped by the preceding ones. Sutures on the spiral side curved in direction of coiling, those on the umbilical side more or less straight to slightly curved backward. Umbilicus large, subcircular, with fragments of covering plate along truncate edges of chambers. Aperture large, elongate-arcuate, with minute liplike projection leading into the umbilicus. Wall apparently thick, surface coarsely rugose, especially in earlier chambers. Ornamentation suggesting a variant of the meridional pattern of Rugoglobigerina.

Distinguishing features: Test in flat trochospiral, chambers enlarging rapidly as added, early ones globular, later chambers compressed to rhomboidal in section, imperforate carinal band or faint keel in the final whorl, sutures radial, depressed, peripheral margin rounded to truncate, peripheral outline lobulate; wall calcareous, perforate, surface covered with prominent pustules and costellae in meridional arrangement, less prominent on the final chamber; primary aperture interiomarginal, umbilical, bordered by an imperforate flap, those of successive chambers fusing into a tegillum having both proximal and distal accessory apertures.

Geological Range: Last occurrence (top): within Maastrichtian Stage (66.04-72.05Ma, top in Maastrichtian stage). Data source: Total of range of species in this databaseFirst occurrence (base): within Campanian Stage (72.05-83.64Ma, base in Campanian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Dec 2017 - Plotting of Neptune data has been re-enabled on the Mesozoic pages following revision of the age-models in Neptune. The data is, however, still very sparse for the Early Cretaceous